NK cells developing in vitro from immature progenitors express at least one member of the Ly49 family that is acquired in a time-dependent and stochastic manner independently of CD94 and NKG2.

Karen P. Fraser*, Frances Gays*, John H. Robinson*, Katrien van Beneden #, Georges Leclercq#, Russell E. Vance$, David H. Raulet$, and Colin G. Brooks*.


The *Department of Microbiology and Immunology, The Medical School, Newcastle NE2 4HH, United Kingdom,  #The Department of Clinical Chemistry, Microbiology, and Immunology, Ghent University, University Hospital, B-9000 Ghent, Belgium, and $Department of Molecular and Cell Biology and Cancer Research Laboratory, University of California at Berkeley, California 94720, U.S.A.


Introduction

Figure 1     NK cells developing in vitro from early thymic progenitors progressively acquire Ly49 molecules recognized by the mAb 4D12

Figure 2     A second mAb that recognizes Ly49E, 14B11, stains the same subpopulation of developing NK cells as 4D12

Figure 3     NK cells developing in vitro from early thymic progenitors also progressively acquire CD94 molecules but with different kinetics than those associated with the acquisition of Ly49 molecules

Figure 4     NKG2-expressing NK cells develop exactly in parallel with CD94 hi NK cells

Figure 5     Amongst both adult splenic NK cells and NK cells that develop in vitro from early thymic progenitors those that express NKG2 are identical to those that express high levels of CD94

Figure 6     All Qa1 receptors on adult NK cells and on NK cells that develop in vitro from early thymic progenitors contain NKG2 molecules

Figure 7     During NK cell development in vitro the acquisition of high levels of CD94 and of Qa1 receptors occurs independently of the acquisition of Ly49 molecules

Figure 8     Individual thymic progenitors can develop into populations of NK cells that show highly diverse expression of CD94/NKG2 receptors and Ly49 molecules

Figure 9     CD94/NKG2 receptors can be expressed on developing NK cells in the absence of NK1.1

Figure 10   NK1.1 molecules are rapidly expressed on NK cell progenitors following exposure to IL2

Figure 11   The presence of IL4 during the later stages of NK cell development in vitro completely blocks the acquisition of CD94/NKG2 and Ly49 molecules, but has little effect on the expression of NKRP1 molecules

Acknowledgements